Some consumer electronics equipment has already been designed with power saving features. A “standby” mode is a power saving mode that reduces electrical power consumption when the electronic device is idle. Standby mode places the electronic device into a state of “waiting for a power-up command”. However, power consumption can still be considerable in such a “standby” mode, even though the equipment is not in active use.
Canal+ introduced a digital set-to-box (STB) having a true power cutoff mode built into it meaning that the STB could be completely powered down, thus consuming no power.
However, the majority of consumer electronics equipment currently marketed are not designed with such a power cutoff feature and therefore various after-market devices are available that provide some degree of power control. Such devices include the Standby Saver (www.standby-saver.co.uk/standby-_saver_home.htm) and The Savasocket (www.thesavasocket.co.uk/savasocket.html). These are timer-based, mains-power control devices that the consumer equipment is plugged into. The device turns the power on or off according to a preset timer that forms part of the device.
International patent application published as WO 2004/057862 describes an appliance, such as a set top box, that has an ON power mode and a STAND BY power mode and that is in communication with a television set. A parameter of an operating signal associated with the television set is monitored and the value of the parameter is compared with predetermined values at which the set top box is desired to be either operative (ON power mode) or inoperative (STAND BY power mode). When a predetermined value of the parameter is detected, the current power mode of the set top box is evaluated and, if necessary, changed. Power supply to the TV set, operating frequency of a local oscillator/mixer in the TV set or the presence of a line scan signal from the TV set rate can be monitored to determine whether the appliance should be turned on or off.
U.S. Pat. No. 6,292,233 describes a device controller that controls access to a device, such as a television, and that has a power input for receiving power and a data input for receiving control data. When in standby mode, the device controller disconnects the device from a power source, such as the AC mains of the building in which the device is situated. As a result, in standby mode only the device controller is powered, which uses much less power than prior art devices in standby mode. The device controller includes an input device structured to provide control data based on control instructions received from a user, a power switch coupled between a power source and the device power input, and a data coupler coupled to the device data input and structured to convert electrical data into non-electrical data and back to the electrical data for delivery to the device data input. The device controller also includes a controller structured to cause the data coupler to provide the control data to the device data input, decode the control data, and if the control data indicates that the user desires to turn on the device when in standby mode, then causes the power switch to deliver power from the power source to the device power input.
European patent application EP0975109 describes a digital broadcasting method for transmitting required information to minimize the stand-by power in an apparatus for receiving a digital broadcast, and the receiving apparatus. Before transmitting utilization data for an apparatus at the receiving end from a transmitting end, transmission schedule information including the kind of the utilization data, a receiver identifier indicating a target to which the utilization data is to be transmitted, and the transmission time at which the utilization data is to be transmitted, is multiplexed in a transport stream of a service (program) to be transmitted.